The law firms want to deny appraisal rights to hedge funds that buy shares after the record date. This way, the firms say, the law can better protect the long-term shareholders that it was supposed to protect.

Barbara Becker, co-chair of Gibson Dunn’s M&A practice, and Saee Muzumdar, corporate associate, led the team that advised Tenet on three recent deals that were signed simultaneously: a joint venture with Welsh, Carson, Anderson & Stowe and United Surgical Partners International; an acquisition in the United Kingdom from Welsh Carson;...